[Effect of sirolimus combined with anti-CD20 monoclonal antibody desensitization on the prognosis of patients underwent haploidentical stem cell transplantation].

Objective: To investigate the effects of sirolimus combined with anti-CD20 monoclonal antibody desensitization on the prognosis of patients with haploidentical stem cell transplantation (haplo-SCT). Methods: Fifteen consecutive patients who received haplo-SCT and pre-transplant donor specific anti-human leukocyte antigen (HLA) antibody (DSA) positive [mean fluorescence intensity (MFI)≥2 000] in the Institute of Hematological Diseases from November 2021 to March 2023 were retrospectively recruited into the desensitized group. There were 4 males and 11 females, with a median age [M(Q1, Q3)] of 48 (37, 59) years. All patients were desensitized with sirolimus combined with anti-CD20 monoclonal antibody. The non-desensitized group included 29 patients with haplo-SCT who had not received desensitization treatment from August 2012 to June 2016. There were 12 males and 17 females with a median age of 42 (26, 50) years. Up to October 1, 2023, the median follow-up time was 13 (9, 18) months in the study group and 23 (14, 29) months in the control group. The changes of MFI before and after desensitization treatment and the prognosis of patients in the desensitized group were compared, including the incidence of primary implantation failure (pGF), neutrophil implantation time, platelet implantation time, grade Ⅱ-Ⅳ acute graft-versus-host disease (GVHD) and chronic GVHD incidence, non-recurrence related mortality, event-free survival rate, disease-free survival rate and overall survival rate. The survival curve was drawn by Kaplan-Meier method, and the survival rate between groups was compared with Log-rank test. Results: After desensitization treatment, the level of DSA MFI in the desensitized group decreased from 8 879 (7 544, 11 495) to 3 781 (1 638, 4 165) after desensitization treatment (P<0.01). All of the patients achieved hematopoietic recovery, and the median time for neutrophil and platelet engraftment were 14 (11, 15) and 20 (18, 25) days, respectively. The incidence of pGF in the desensitized group was 0, which was lower than that in the non-desensitized group (34.5%, 10/29) (P=0.011). The expected 1-year disease-free survival rate and overall survival rate in the desensitized group were 100% (15/15) and 100% (15/15) respectively, while those in the non-desensitized group were 75.9% (22/29) and 75.9% (22/29) respectively, the difference was not statistically significant (both P>0.05). The one-year event-free survival rate in the desensitized group was expected to be 100% (15/15), which was higher than that in the non-desensitized group (51.3%, 15/29) (P=0.002). Conclusion: Sirolimus combined with anti-CD20 monoclonal antibody desensitization therapy can reduce the DSA level of haplo-SCT recipients, promote hematopoietic engraftment after transplantation, and avoid the occurrence of pGF after transplantation.

[Clinical significance of Epstein-Barr Virus detection in the cerebrospinal fluid of patients who underwent hematopoietic stem cell transplantation].

Objective: To analyze the detection rate, clinical significance, and prognosis of Epstein-Barr virus (EBV) in the cerebrospinal fluid (CSF) of patients following allogeneic hematopoietic stem cell transplantation. Methods: A retrospective analysis was performed on 1100 patients who underwent the CSF virus test after allogeneic hematopoietic stem cell transplantation in Peking University People's Hospital between January 2017 and June 2022. Among them, 19 patients were screened positive for EBV in their CSF, and their clinical characteristics, treatment, and prognosis were analyzed. Results: Among 19 patients with EBV-positive cerebrospinal fluid, 12 were male and 7 were female, with 5 patients aged <18 years and 12 aged ≥18 years, with a median age of 27 (5-58) years old. There were 7 cases of acute myeloid leukemia, 8 of acute lymphocytic leukemia, 2 of aplastic anemia, 1 of Hodgkin's lymphoma, and 1 of hemophagocytic syndrome. All 19 patients underwent haploid hematopoietic stem cell transplantation, including 1 secondary transplant. Nineteen patients had neurological symptoms (headache, dizziness, convulsions, or seizures), of which 13 had fever. Ten cases showed no abnormalities in cranial imaging examination. Among the 19 patients, 6 were diagnosed with EB virus-related central nervous system diseases, with a median diagnosis time of 50 (22-363) days after transplantation. In 9 (47.3%) patients, EBV was detected in their peripheral blood, and they were treated with intravenous infusion of rituximab (including two patients who underwent lumbar puncture and intrathecal injection of rituximab). After treatment, EBV was not detected in seven patients. Among the 19 patients, 2 died from EBV infection and 2 from other causes. Conclusion: In patients who exhibited central nervous system symptoms after allogeneic hematopoietic stem cell transplantation, EBV should be screened as a potential pathogen. EBV detected in the CSF may indicate an infection; however, it does not confirm the diagnosis.

[Prognostic analysis of patients with acute leukemia and central nervous system involvement undergoing allogeneic hematopoietic stem cell transplantation].

Objective: To investigate the potential of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in mitigating the adverse prognosis associated with central nervous system leukemia (CNSL) and to assess the significance of prophylactic intrathecal injection. Methods: A retrospective cohort analysis was conducted involving 30 patients with acute leukemia who had a history of CNSL who underwent allo-HSCT at Peking University People's Hospital between September 2012 and March 2018 (referred to as the CNSL-positive group). In addition, 90 patients with acute leukemia were selected from the same period who underwent allo-HSCT without a history of CNSL (referred to as the CNSL-negative group) and a rigorous 1∶3 matching was performed based on disease type, disease status, and transplantation type to form the control group. The prognosis between the two groups was compared using Kaplan-Meier analysis and the high-risk factors for CNSL relapse post-transplant were identified through Cox proportional-hazards model. Results: The median age of patients in the CNSL-negative group was significantly higher than that of patients in the CNSL-positive group (32 years vs. 24 years, P=0.014). No significant differences were observed in baseline data, including sex, disease type, disease status at transplantation, donor-recipient relationship, and human leukocyte antigen consistency between the two groups. The median follow-up time was 568 days (range: 21-1 852 days). The 4-year cumulative incidence of relapse (71.4%±20.9% vs. 29.3%±11.5%, P=0.005) and the cumulative incidence of CNSL post-transplant (33.6%±9.2% vs. 1.2%±1.2%, P<0.001) were significantly higher in the CNSL-positive group than in the CNSL-negative group. Furthermore, the 4-year leukemia-free survival rate in the CNSL-positive group was significantly lower than that in the CNSL-negative group (23.1%±17.0% vs. 71.5%±11.6%, P<0.001). However, no significant differences were observed in the 4-year cumulative transplant-related mortality and overall survival rates between the two groups (both P>0.05). Multivariate analysis revealed that a history of CNSL before transplantation (HR=25.050, 95%CI 3.072-204.300, P=0.003) was identified as high-risk factors for CNSL relapse post-transplant. Conversely, haploidentical transplantation was associated with a reduced risk of CNSL relapse post-transplant (HR=0.260, 95%CI 0.073-0.900, P=0.034). Within the CNSL-positive group, seven patients received prophylactic intrathecal therapy after transplantation, and their CNSL relapse rate was significantly lower than that of the 23 patients who did not receive intrathecal therapy after transplantation (0/7 vs. 9/23, P=0.048). Conclusions: Patients with a history of CNSL have a higher risk of relapse and experience poorer leukemia-free survival following transplantation. The use of prophylactic intrathecal injection shows promise in mitigating CNSL relapse rates, although further validation through prospective studies is necessary to substantiate these observations.

[Safety and survival analysis of haplo-identical hematopoietic stem cell transplantation in patients with severe aplastic anemia who had previous failure to antithymoglobulin treatment].

Objective: To investigate the safety and efficacy of haplo-identical hematopoietic stem cell transplantation (haplo-HSCT) conditioning with the same dosage form of antithymoglobulin (ATG) in patients with severe aplastic anemia (SAA) failure to ATG. Methods: This was a retrospective cohort study. A total of 65 patients with SAA who failed ATG treatment and received haplo-HSCT conditioning with the same dosage of ATG at the Institute of Hematology, Peking University People's Hospital between July 2008 and October 2020 were included as the ATG treatment failure group. An additional 65 SAA patients who applied ATG for the first time during haplo-HSCT were randomly selected by stratified sampling as the first-line haplo-HSCT group. Baseline clinical data and follow-up data of the two groups were collected. Conditioning-related toxicity within 10 days after ATG application and long-term prognosis were analyzed. The Kaplan-Meier was used to calculate the overall survival rate, and the Log-rank test was applied to compare the rates of the two groups. Results: In the ATG treatment failure group, there were 36 males and 29 females, and the age at the time of transplantation [M (Q1, Q3)] was 16 (8, 25) years. In the first-line haplo-HSCT group, there were 35 males and 30 females, with a median age of 17 (7, 26) years. Within 10 days of ATG application, the incidence of noninfectious fever, noninfectious diarrhea, and liver injury in the ATG treatment failure group was 78% (51 cases), 45% (29 cases), and 28% (18 cases), respectively, and in the first-line haplo-HSCT group was 74% (48 cases), 54% (35 cases), and 25% (16 cases), respectively; the difference between the two groups was not statistically significant for any of these three parameters (all P>0.05). For graft-versus-host disease (GVHD), there was no significant difference between the ATG treatment failure group and the first-line haplo-HSCT group in the development of 100 day Ⅱ to Ⅳ acute GVHD (29.51%±0.35% vs. 25.42%±0.33%), Ⅲ to Ⅳ acute GVHD (6.56%±0.10% vs. 6.78%±0.11%), and 3-year chronic GVHD (26.73%±0.36% vs. 21.15%±0.30%) (all P>0.05). Three-year overall survival (79.6%±5.1% vs. 84.6%±4.5%) and 3-year failure-free survival (79.6%±5.1% vs. 81.5%±4.8%) were also comparable between these two groups (both P>0.05). Conclusions: Compared with no exposure to ATG before HSCT, similar early adverse effects and comparable survival outcomes were achieved in patients with SAA who failed previous ATG treatment and received haplo-HSCT conditioning with the same dosage form of ATG. This might indicate that previous failure of ATG treatment does not significantly impact the efficacy and safety of salvaging haplo-HSCT in patients with SAA.

[Clinical analysis of the usefulness of letermovir for prevention of cytomegalovirus infection after haploidentical hematopoietic stem cell transplantation].

Objective: To analyze the efficacy and safety of letermovir in primary prophylaxis of cytomegalovirus (CMV) reactivation in patients receiving haploidentical hematopoietic stem cell transplantation. Methods: This retrospective, cohort study was conducted using data of patients who underwent haploidentical transplantation at Peking University Institute of Hematology and received letermovir for primary prophylaxis between May 1, 2022 and August 30, 2022. The inclusion criteria of the letermovir group were as follows: letermovir initiation within 30 days after transplantation and continuation for≥90 days after transplantation. Patients who underwent haploidentical transplantation within the same time period but did not receive letermovir prophylaxis were selected in a 1∶4 ratio as controls. The main outcomes were the incidence of CMV infection and CMV disease after transplantation as well as the possible effects of letermovir on acute graft versus host disease (aGVHD), non-relapse mortality (NRM), and bone marrow suppression. Categorical variables were analyzed by chi-square test, and continuous variables were analyzed by Mann-Whitney U test. The Kaplan-Meier method was used for evaluating incidence differences. Results: Seventeen patients were included in the letermovir prophylaxis group. The median patient age in the letermovir group was significantly greater than that in the control group (43 yr vs. 15 yr; Z=-4.28, P<0.001). The two groups showed no significant difference in sex distribution and primary diseases, etc. (all P>0.05). The proportion of CMV-seronegative donors was significantly higher in the letermovir prophylaxis group in comparison with the control group (8/17 vs. 0/68, χ2=35.32, P<0.001). Three out of the 17 patients in the letermovir group experienced CMV reactivation, which was significantly lower than the incidence of CMV reactivation in the control group (3/17 vs. 40/68, χ2=9.23, P=0.002), and no CMV disease development observed in the letermovir group. Letermovir showed no significant effects on platelet engraftment (P=0.105), aGVHD (P=0.348), and 100-day NRM (P=0.474). Conclusions: Preliminary data suggest that letermovir may effectively reduce the incidence of CMV infection after haploidentical transplantation without influencing aGVHD, NRM, and bone marrow suppression. Prospective randomized controlled studies are required to further verify these findings.

[Dynamic monitoring of plasma Epstein-Barr Virus DNA load can predict the occurrence of lymphoproliferative disorders after haploidentical hematopoietic stem cell transplantation].

Objective: To determine the optimal cutoff value of Epstein-Barr virus (EBV) DNA load that can assist in the diagnosis of post-transplant lymphoproliferative disease (PTLD) after haploidentical hematopoietic stem cell transplantation (haplo-HSCT) . Methods: The data of patients with EBV infection after haplo-HSCT from January to December 2016 were retrospectively analyzed. Through constructing the receiver operating characteristic (ROC) curve and calculating the Youden index to determine the cutoff value of EBV-DNA load and its duration of diagnostic significance for PTLD. Results: A total of 94 patients were included, of whom 20 (21.3% ) developed PTLD, with a median onset time of 56 (40-309) d after transplantation. The median EBV value at the time of diagnosis of PTLD was 70,400 (1,710-1,370,000) copies/ml, and the median duration of EBV viremia was 23.5 (4-490) d. Binary logistic regression was used to analyze the peak EBV-DNA load (the EBV-DNA load at the time of diagnosis in the PTLD group) and duration of EBV viremia between the PTLD and non-PTLD groups. The results showed that the difference between the two groups was statistically significant (P=0.018 and P=0.001) . The ROC curve was constructed to calculate the Youden index, and it was concluded that the EBV-DNA load ≥ 41 850 copies/ml after allogeneic hematopoietic stem cell transplantation had diagnostic significance for PTLD (AUC=0.847) , and the sensitivity and specificity were 0.611 and 0.932, respectively. The duration of EBV viremia of ≥20.5 d had diagnostic significance for PTLD (AUC=0.833) , with a sensitivity and specificity of 0.778 and 0.795, respectively. Conclusion: Dynamic monitoring of EBV load in high-risk patients with PTLD after haplo-HSCT and attention to its duration have important clinical significance, which can help clinically predict the occurrence of PTLD in advance and take early intervention measures.

[Incidence and clinical characteristics of engraftment syndrome after syngeneic hematopoietic stem cell transplantation in patients with hematological diseases].

Objective: To explore the incidence and clinical characteristics of engraftment syndrome (ES) after syngeneic hematopoietic stem cell transplantation (syn-HSCT) in patients with hematological diseases. Methods: The clinical data of 21 patients who received syn-HSCT at People's Hospital of Peking University from January 1994 to May 2018 were retrospectively analyzed. Results: Seven (33.3% ) of 21 patients developed ES. The onset of ES symptoms occurred at a median of 8 (range: 5-13) days after HSCT, and the diagnosis of ES occurred at a median of 10 (range: 7-14) days after HSCT. Steroids were administered immediately after the diagnosis of ES, the median time of symptom continuance was 2 (range: 1-5) days, and all patients showed complete resolution of ES symptoms. In the multivariate analysis, patients with acute myeloid leukemia and faster neutrophil reconstitution were the risk factors for ES (HR=15.298, 95% CI 1.486-157.501, P=0.022, and HR=17.459, 95% CI 1.776-171.687, P=0.014) . Meanwhile, there was no significant difference in the overall survival and disease-free survival between patients with ES and those without ES. Conclusion: A high incidence of ES was observed in syn-HSCT recipients. Moreover, the prognosis of ES was excellent.

[Clinical analysis of 11 patients with neuroendocrine carcinoma in maxillofacial region].

Objective: To investigate the clinicopathological features, treatment and prognosis of maxillofacial neuroendocrine carcinoma. Methods: A total of 11 patients with maxillofacial neuroendocrine carcinoma diagnosed in the Department of Pathology of The First Affiliated Hospital of Zhengzhou University from December 2010 to July 2022 were retrospectively enrolled, including 8 males and 3 females, aged (65.2±9.5) years (ranged from 49 to 87 years), with a disease course of 0.5 to 6.0 months. The clinicopathological data including head and neck CT, MRI and treatment methods were analyzed. Results: Submandibular gland and maxilla were involved in 3 cases, parapharynx in 2 cases, and face, tongue root and soft palate in 1 case respectively. Clinically, the initial symptom is a rapidly growing painless or tender mass, which may be accompanied by restricted mouth opening, dysphagia, and local numbness after invasion of masticatory muscles and nerves. The tumors were all invasive and low-density, with unclear boundaries from the surrounding tissues. Among the patients, 9 received surgical treatment, and 5 received adjuvant treatment after surgery (2 received chemotherapy, 3 received radiotherapy+chemotherapy). According to the 5th edition of the World Health Organization classification of head and neck tumors in 2022, there were 1 case (1/11) with poorly differentiated large cells and 10 cases (10/11) with poorly differentiated small cells. Histologically, the macrocell type is composed of large cells with rough chromatin, obvious vacuolar nucleolus, protruding nucleolus, and necrosis. The small cell type is dominated by small blue round cells with neuroendocrine characteristics, with active growth and multifocal necrosis. Immunohistochemical staining showed that cytokeratin (CK), epithelial membrane antigen (EMA) and synaptophysin (Syn) were diffusively expressed, 10 cases expressed CD56, 8 cases expressed p63, 6 cases expressed weakly punctated chromograin-A (CgA), and S-100 was not expressed. The Ki-67 index ranges from 20 to 90 percent. By the end of follow-up (0.5 to 127.0 months), 3 patients were alive, and the mean progression-free survival (21.0 months) of postoperative chemoradiotherapy patients was significantly longer than that of surgery and/or chemotherapy alone (3.3 months). Conclusions: Maxillofacial neuroendocrine carcinoma is characterized by low differentiation of small cells, high degree of malignancy and poor prognosis. Radical surgery combined with chemoradiotherapy has better local control effect.

[Clinical analysis of the efficacies of ganciclovir plus foscarnet and a single antiviral drug for the treatment of cytomegalovirus infection after haploidentical stem cell transplantation].

Objective: To evaluate and compare the efficacies of ganciclovir plus foscarnet and a single agent for the treatment of cytomegalovirus (CMV) infection after haploidentical hematopoietic stem cell transplantation. Methods: This study was a non-randomized clinical controlled trial. The data of patients who underwent haploidentical transplantation and developed CMV infection between January 1, 2021, and June 30, 2021, were retrospectively analyzed. Follow-up was conducted through telephone, inpatient consultations, and the review of outpatient medical records. The observed indicators included the incidence of CMV infection (including CMV disease), rate of recurrence of CMV infection, overall survival (OS), and disease-free survival (DFS). Results: A total of 242 patients were diagnosed with post-transplantation CMV infection; 116 patients tested positive for CMV DNA for more than 14 days (P=0.011). Of the 242 patients with CMV infection, 65 were treated with ganciclovir plus foscarnet, and 156 patients were treated with a single antiviral drug; the median durations of CMV seroconversion were 21 (3-60) and 14 (3-32) days for the combination and single-drug groups, respectively. There were no significant differences between their incidence of CMV infections and 1-year OS and DFS. Of the patients with refractory CMV infections, 53 (45.7%) were treated with ganciclovir plus foscarnet, and 63 (54.3%) were treated with a single antiviral agent. The median durations of CMV seroconversion for the combination and single-drug groups were 21 (15-60) days and 20 (15-45) days, respectively (P=0.472). Two patients in each group progressed to CMV disease (P=0.860). During follow-up, 12 patients (22.6%) in the combination group and 8 patients (12.7%) in the single-drug group experienced recurrent episode(s) of CMV infection (P=0.158). The 1-year OS of the combination and single-drug groups were 92.0% and 87.1%, respectively (P=0.543); the 1-year DFS were 90.3% and 85.7%, respectively (P=0.665). Univariate analysis revealed no associations between the antiviral agents used and OS and DFS (OS: HR=0.644, P=0.547; DFS: HR=0.757, P=0.666). Conclusions: There were no significant differences in the duration of CMV infection, incidence of CMV disease, rate of recurrence of CMV infection, and survival of the patients treated with the combination of antiviral drugs and a single antiviral drug.

[Comparison of the characteristics of NK cells after two different methods of expansion and observation of the clinical efficacy in patients who relapsed post allogeneic hematopoietic stem cell transplantation].

Objective: To explore the differences in the biological effects of different expansion systems on natural killer (NK) cells, as well as the safety and preliminary clinical efficacy in the treatment of patients with recurrence after allogeneic hematopoietic stem cell transplantation (allo-HSCT) . Methods: Peripheral blood cells from healthy donors were stimulated with either CD3 combined with CD52 or K562 feeder cells loaded with IL-21/4-1BB to induce NK cell expansion. Changes in the NK cell phenotype, cytokine secretion, and cytotoxicity before and after expansion were detected. We also evaluated the safety and clinical efficacy of two different expansion strategies for patients received NK infusion. Results: Compared with the CD3/CD52 monoclonal antibody amplification system, the feeder cell expansion group had a higher purity of NK cells and higher expression ratios of NK cell surface activation receptors such as DNAM-1 and NKp30, while inhibitory receptor CTLA-4 expression was low and NKG2D/CD25/CD69/ Trail/PD-1/TIM-3/TIGIT had no statistically significant differences between the groups. Further functional results showed that the expression level of KI67 in NK cells after expansion in the two groups increased significantly, especially in the feeder cell expansion group. Simultaneously, the perforin and granzyme B levels of NK cells in the feeder cell expansion group were significantly higher than in the CD3/CD52 expansion group. A retrospective analysis of eight patients who received monoclonal antibody-expanded NK cell reinfusion and nine patients with trophoblast cell-expanded NK cell reinfusion was done. The disease characteristics of the two groups were comparable, NK cell reinfusion was safe, and there were no obvious adverse reactions. Clinical prognostic results showed that in the CD3/CD52 monoclonal antibody amplification group, the MRD conversion rate was 50% (2/4) , and the feeder cell expansion group was 50% (3/6) . After 5 years of follow-up from allo-HSCT, three patients in the monoclonal antibody expansion group had long-term survival without leukemia, and the remaining five patients had died; two patients died in the feeder cell expansion group, and the other six patients had long-term survival. Six cases had GVHD before NK cell reinfusion, and GVHD did not aggravate or even relieved after NK cell reinfusion. Conclusions: Preliminary results show that the biological characteristics of NK cells with diverse expansion strategies are significantly different, which may affect the clinical prognosis of patients with recurrence or persistent minimal residual disease after HSCT. The two groups of patients treated with NK cells from different expansion strategies had no obvious adverse reactions after NK cell infusion, but efficacy still needs to be further confirmed.

[Clinicopathological characteristics and differential diagnosis of 6 cases of congenital granular cell tumor].

To provide references for the diagnosis and treatment of congenital granular cell tumor (CGCT), by comprehensive analysis of the clinical data, histopathological and immunohistochemical results. Patients with CGCT were involede, from March 2015 to November 2020, at the Department of Oral and Maxillofacial Surgery of the First Affiliated Hospital of Zhengzhou University. A total of 6 children, aged 3-16 days, 1 male and 5 female, 5 maxillary and 1 mandibular, with maximum tumor diameter of 6-70 mm, were included. The lesions of CGCT were single and connected to the alveolar ridge by a pedicle. The surface of the tumor was covered with a vascular network, and two cases had ulcers on the surface of the tumor. All 6 cases had the tumor removed surgically and there was no recurrence or metastasis in the follow-up visit. Although CGCT is rare, it is a benign tumor and generally does not recur or metastasize after surgery, and has a good prognosis. The prenatal imaging, clinical manifestations after delivery, pathological characteristics and immunohistochemical analyses may provide reference for early diagnosis and treatment of CGCT.

[A retrospective comparative study of haplotype hematopoietic stem cell transplantation and human leukocyte antigen-matched sibling donor hematopoietic stem cell transplantation in the treatment of acute B-lymphocyte leukemia].

Objective: To investigate whether haplotype hematopoietic stem cell transplantation (haplo-HSCT) is effective in the treatment of pre transplant minimal residual disease (Pre-MRD) positive acute B lymphoblastic leukemia (B-ALL) compared with HLA- matched sibling donor transplantation (MSDT) . Methods: A total of 998 patients with B-ALL in complete remission pre-HSCT who either received haplo-HSCT (n=788) or underwent MSDT (n=210) were retrospectively analyzed. The pre-transplantation leukemia burden was evaluated according to Pre-MRD determinedusing multiparameter flow cytometry (MFC) . Results: Of these patients, 997 (99.9% ) achieved sustained, full donor chimerism. The 100-day cumulative incidences of neutrophil engraftment, platelet engraftment, and grades Ⅱ-Ⅳ acute graft-versus-host disease (GVHD) were 99.9% (997/998) , 95.3% (951/998) , and 26.6% (95% CI 23.8% -29.4% ) , respectively. The 3-year cumulative incidence of total chronic GVHD was 49.1% (95% CI 45.7% -52.4% ) . The 3-year cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) of the 998 cases were 17.3% (95% CI 15.0% -19.7% ) and 13.8% (95% CI 11.6% -16.0% ) , respectively. The 3-year probabilities of leukemia-free survival (LFS) and overall survival (OS) were 69.1% (95% CI 66.1% -72.1% ) and 73.0% (95% CI 70.2% -75.8% ) , respectively. In the total patient group, cases with positive Pre-MRD (n=282) experienced significantly higher CIR than that of subjects with negative Pre-MRD [n=716, 31.6% (95% CI 25.8% -37.5% ) vs 14.3% (95% CI 11.4% -17.2% ) , P<0.001]. For patients in the positive Pre-MRD subgroup, cases treated with haplo-HSCT (n=219) had a lower 3-year CIR than that of cases who underwent MSDT [n=63, 27.2% (95% CI 21.0% -33.4% ) vs 47.0% (95% CI 33.8% -60.2% ) , P=0.002]. The total 998 cases were classified as five subgroups, including cases with negative Pre-MRD group (n=716) , cases with Pre-MRD<0.01% group (n=46) , cases with Pre-MRD 0.01% -<0.1% group (n=117) , cases with Pre-MRD 0.1% -<1% group (n=87) , and cases with Pre-MRD≥1% group (n=32) . For subjects in the Pre-MRD<0.01% group, haplo-HSCT (n=40) had a lower CIR than that of MSDT [n=6, 10.0% (95% CI 0.4% -19.6% ) vs 32.3% (95% CI 0% -69.9% ) , P=0.017]. For patients in the Pre-MRD 0.01% -<0.1% group, haplo-HSCT (n=81) also had a lower 3-year CIR than that of MSDT [n=36, 20.4% (95% CI 10.4% -30.4% ) vs 47.0% (95% CI 29.2% -64.8% ) , P=0.004]. In the other three subgroups, the 3-year CIR was comparable between patients who underwent haplo-HSCT and those received MSDT. A subgroup analysis of patients with Pre-MRD<0.1% (n=163) was performed, the results showed that cases received haplo-HSCT (n=121) experienced lower 3-year CIR [16.0% (95% CI 9.4% -22.7% ) vs 40.5% (95% CI 25.2% -55.8% ) , P<0.001], better 3-year LFS [78.2% (95% CI 70.6% -85.8% ) vs 47.6% (95% CI 32.2% -63.0% ) , P<0.001] and OS [80.5% (95% CI 73.1% -87.9% ) vs 54.6% (95% CI 39.2% -70.0% ) , P<0.001] than those of MSDT (n=42) , but comparable in 3-year NRM [5.8% (95% CI 1.6% -10.0% ) vs 11.9% (95% CI 2.0% -21.8% ) , P=0.188]. Multivariate analysis showed that haplo-HSCT was associated with lower CIR (HR=0.248, 95% CI 0.131-0.472, P<0.001) , and superior LFS (HR=0.275, 95% CI 0.157-0.483, P<0.001) and OS (HR=0.286, 95% CI 0.159-0.513, P<0.001) . Conclusion: Haplo HSCT has a survival advantage over MSDT in the treatment of B-ALL patients with pre MRD<0.1% .

[Incidence and clinical significance of platelet transfusion refractoriness after allogeneic hematopoietic stem cell transplantation in patients with chronic myelomonocytic leukemia].

Objective: To retrospectively analyze the incidence and clinical significance of platelet transfusion refractoriness (PTR) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with chronic myelomonocytic leukemia (CMML) . Methods: A cohort of 55 CMML patients received allo-HSCT at Peking University Institute of Hematology during 2004-2021 were retrospectively assessed. The incidence of PTR within 30 days after allo-HSCT was retrospectively analyzed, and the impact on clinical outcomes and bleeding event were compared between patients with platelet transfusion refractoriness (PTR) or effective platelet transfusion (EPT) . Results: The incidence of PTR after allo-HSCT in CMML patients was 25.5% (14/55) . PTR patients had a lower rate of platelet engraftment than EPT patients (28.6% vs 100%) , and the median time of engraftment was 67 (33-144) days and 21 (9-157) days respectively (P<0.010) . There was no significant difference between two groups in acute graft-versus-host disease (aGVHD) and chronic graft-versus-host disease (cGVHD) (P=0.183, P=0.455) . After following-up a median of 684 (24-3978) days, the 1-year overall survival (OS) and 1-year leukemia free survival (LFS) in PTR and EPT patients were (35.4±13.9) % vs (75.1±7.8) % (P=0.037) and (28.1±13.3) % vs (65.3±8.2) % (P=0.072) , respectively. The transplant-related mortality (TRM) were (48.2±2.4) % and (9.0±0.25) %, respectively (P=0.009) . Bleeding events occurred in five patients (35.7%) of PTR and 2 patients (4.9%) of EPT (P=0.009) . Conclusion: In CMML patients with allo-HSCT, the incidence of PTR is 25.5%, which was associated with delayed platelet engraftment, increased bleeding events, inferior OS and increased TRM.

[Safety of rabbit anti-human thymocyte immunoglobulin in second allogeneic hematopoietic stem cell transplantation for patients with hematological diseases].

Objective: To look into the security of a second allogeneic hematopoietic stem cell transplantation (allo-HSCT) using rabbit anti-human thymocyte immunoglobulin (rATG) . Methods: Twenty-seven patients who used rATG in the first and second allo-HSCT at the Institute of Hematology, Peking University were enrolled in the study. Experienced toxicities associated with the conditioning protocol within 10 days (-5 d to +3 d) following the beginning of the rATG application, including fever, diarrhea, arrhythmia, reduced blood pressure, liver damage, seizures, and other problems. Results: The overall incidence of conditioning regimen early adverse reactions during the first transplantation and the second allo-HSCT conditioning regimen was 96.3% and 77.8% (P=0.043) . Fever rates were 81.5% and 63.0% (P=0.129) , diarrhea rates were 59.3% and 25.9% (P=0.013) , liver damage rates were 22.2% and 25.9% (P=0.75) , and the rates of other events (cardiac arrhythmia, low blood pressure, and epilepsy) were 3.7% and 18.5% (P=0.083) . Adverse reactions that occurred during both the first and second course of rATG applications have been improved with symptomatic treatment, and no treatment interruptions occurred. Conclusion: Reusing rATG in a second transplant was risk-free and did not result in higher early toxicities.

[BK virus encephalitis in children with hematopoietic stem cell transplantation].

Objective: To explore the morbidity, mortality, median onset time, clinical characteristics, diagnosis, treatment, and outcome of BK virus (BKV) central nervous system infection in children with allogeneic hematopoietic stem cell transplantation (allo-HSCT) , and improve the understanding, clinical diagnosis, and treatment of the disease. Methods: Seven hundred and nine children who received haploid HSCT treatment in Peking University People's Hospital from January 1, 2015 to December 31, 2020 were reviewed. Fourteen patients were diagnosed with BKV central nervous system infection, and their clinical characteristics, treatment process, and prognosis were analyzed. Results: The incidence of BKV central nervous system infection was 1.97% (14 cases) , mostly in men (12 cases) , with a median age of 11 years old and median onset time of 55 d. Additionally, most of the cases showed disturbance of consciousness and seizures (seven cases) . Furthermore, 14 cases were treated with acyclovir and ganciclovir alone or with gamma globulin. Nine cases were cured, of which one died of viral encephalitis and four of other diseases, with a mortality rate of 35.7%. Conclusion: Individuals with central nervous system involvement by BKV infection, usually show signs and symptoms of acute encephalitis, with some cases being accompanied by meningeal involvement. Although BKV encephalitis was diagnosed and actively treated with drugs, many patients still died of multiple organ failure or other complications. Therefore, when there are neurological symptoms and hemorrhagic cystitis in patients with allo-HSCT, it is necessary to be highly vigilant against BKV central nervous system infection. This helps to make clear diagnosis and treatment quickly; thus, improving the survival rate and quality of life of patients with HSCT.

[Negative effects of donor specific anti-HLA antibody on poor hematopoietic recovery in patients with hematological diseases receiving haploidentical stem cell transplantation and rituximab for desensitization].

Objective: To investigate the incidences and risk factors of poor hematopoietic reconstitution (PHR) in patients with hematological diseases who underwent haploidentical allograft and were treated with rituximab for desensitization. Methods: Eight-three donor specific anti-HLA antibody (DSA, 2000 ≤MFI<10 000) positive patients who underwent haploidentical allograft were prospectively enrolled. Rituximab (375 mg/m2) was used for desensitization day-3 of conditioning regimen. Incidence and factors associated with PHR, including primary poor graft function and prolonged thrombocytopenia, were investigated. Results: There were 22 males and 61 females with a median age of 39(range: 1-65) years. Kaplan-Meier analysis showed that the 100 day cumulative incidences of neutrophil and platelet engraftment were 93.0% and 90.7%, respectively. The incidences of PHR were 14.7%. The 3-year relapse rate, non-relapse mortality (NRM) rate, event-free survival (EFS), leukemia-free survival (DFS) and overall survival (OS) were 6.5%, 15.1%, 70.8%, 79.4% and 79.4%, respectively. Patients with DSA MFI<5 000 (group A, n=46) experienced lower PHR (4.4% vs. 27.5%, P=0.003), and higher 3-year EFS (79.5% vs. 59.8%, P=0.020) compared to those with DSA MFI≥5 000 (group B, n=37). Multivariate analysis showed that DSA MFI≥5 000 was correlated with PHR (HR=6.101, P=0.021). PHR was associated with higher NRM (HR=4.110, P=0.026), lower DFS (HR=3.656, P=0.019) and OS (HR=3.656, P=0.019). Conclusion: Our data suggest that high pre-transplant DSA level is a risk factor for PHR in patients with hematological diseases receiving haploidentical allograft and rituximab for desensitization.

[The expression and significance of TRPM8 among chronic rhinosinusitis with nasal polyps].

Objective: To compare the expression and difference of melastatin-related transient receptor potential 8(TRPM8) among chronic rhinosinusitis, nasal polyps and normal mucosa tissues. And to explore the significant expression of TRPM8 among CRSwNP. Methods: Fifty-one patients underwent endoscopic sinus surgery in the Department of Otorhinolaryngology Head and Neck Surgery of Renmin Hospital of Wuhan University from February 2019 to January 2020 were recruited, including 33 males and 18 females, aged from 14 to 65 years old (34.55±1.689).Immunohistochemistry was used to detected the expression of TRPM8 protein among CRSsNP(17),CRSwNP (17) and control tissuses(17). In addition, the correlation between the expression of TRPM8 protein in CRSwNP patients and preoperative CT Lund-Mackay scores and preoperative VAS scores and sinonasal outcome test-20 scores was analyzed, respectively. The primary human nasal epithelial cells were cultured in vitro and the expression of TRPM8 was detected by quantitative real-time PCR and western blotting. The tissue in control group, chronic rhinosinusitis without nasal polyps (CRSsNP) group and the CRSwNP group were collected and grinded into tissue homogenized. The expression of TRPM8 protein was detected by western blotting after 24 h stimulation after homogenate was added into the medium of RPMI 2650 and primary nasal epithelial cells. Results: Compared with the control, the expression of TRPM8 was significantly up-regulated in nasal polyps (t=6.852, P<0.05). TRPM8 was mainly expressed in epithelial cells. The expression of TRPM8 in the epithelial cells of CRSsNP had no difference with the control group (t=1.980, P>0.05). In addition, the expression of TRPM8 in CRSwNP patients was positively correlated with the preoperative CT Lund-Mackay scores and VAS scores and SNOT-20 scores (r=0.512, P<0.05;r=0.853, P<0.01;r=0.814, P<0.01). After cultured primary epithelial cells in vitro, the expression level of TRPM8 in epithelial cells derived from nasal polyp was significantly higher than that in control group (t=8.845, P<0.05). By adding the homogenization of control and CRSsNP and CRSwNP tissues, the expression of TRPM8 in RPMI 2650 cells and primary nasal epithelial cells was changed and that was significantly increased after adding the homogenization of the group of CRSwNP. Conclusion: TRPM8 is highly expressed in nasal polyps epithelial cells, suggesting that TRPM8 may be involved in the pathogenesis of nasal polyps regulated by nasal epithelial cells.

[Establishment of human colon cancer transplantation tumor model in normal immune mice].

Objective: Establishment of a new model of human primary colon cancer transplantation tumor in normal immune mice and to provide a reliable experimental animal model for studying the pathogenesis of colon cancer under normal immunity. Methods: Human colon cancer cells come from colon cancer patients who underwent surgery in the Affiliated Hospital of Jining Medical College in 2017. The mice in the cell control group were inoculated with phosphate buffered solution (PBS) containing colon cancer cells, the microcarrier control group was inoculated with PBS containing microcarrier 6, and the cell-microcarrier complex group was inoculated with the PBS containing colon cancer cell-microcarrier complex. The cells of each group were inoculated under the skin of the right axilla of mice by subcutaneous injection, and the time, size, tumor formation rate and pathological changes under microscope were recorded. The transplanted tumor tissue was immunohistochemically stained with the EnVisiion two-step method, and the tumor formation rate of the transplanted tumor was judged according to the proportion of positive cells in the visual field. The polymerase chain reaction (PCR) method was used to detect the expression of human-specific Alu sequence in mice tumor tissue. Results: After inoculation with tumor cells, the mice in the cell control group and the microcarrier control group did not die and did not form tumors; the mice in the cell-microcarrier complex group had palpable subcutaneous tumors in the right axillary subcutaneously on the 5th to 7th days after inoculation, and tumor formation rate is 67% (10/15), and the tumor volume can reach about 500 mm(3) 2 to 3 weeks after vaccination. The immunohistochemistry results showed that CK20, CDX-2 and carcinoembryonic antigen were all positively expressed. The PCR results showed that the expression of human-specific Alu sequence can be detected in the transplanted tumor tissue of tumor-bearing mice. Conclusion: Human primary colon cancer cells used microcarrier 6 as a carrier to form tumors in normal immunized mice, and successfully established a new model of human colon cancer transplantation tumor in normal immune mice.

[Comparison of EB virus infection between short term and long term use of mycophenolate mofetil for prophylaxis of graft versus host disease after haploidentical hematopoietic stem cell transplantation].

Objective: To investigate the role of short-term use of mycophenolate mofetil (MMF) in EB viral infection and acute graft-versus host disease (GVHD) in patients receiving haploidentical hematopoietic stem cell transplantation (haplo-HSCT) . Method: Adult patients (≥14 years) who were diagnosed with hematological malignancies received haplo-HSCT in Peking University Institute of Hematology from May 2016 to December 2017 were retrospectively reviewed. The median age was 30 (14-60) years old. A total of 498 patients including 277 males and 221 females were enrolled. Donors' median age was 38 (8-66) years old. All patients were classified into long-term use of MMF (n=199), which was defined as 500 mg every 12 hours from day 9 pre-transplant to 250 mg every 12 hours from day 30 after transplant then withdrawal on day 45 to 60 after transplant, and short-term use of MMF (n=299), which was defined as 500 mg every 12 hour from day 9 pre-transplant then withdrawal till neutrophil engraftment. Kaplan-Meier model was used to analyze the cumulative incidence of EBV infection, and the Cox proportional regression model for multivariate analysis. Result: Characteristics including sex, age, disease types, mismatched HLA loci, donor-recipient relationship, donor-recipient blood type, donor age, and donor sex were comparable between two groups (all P＞0.05). According to once, the incidence of EBV viremia, defined as EBV＞103 copies/ml at least once, in short-term group and long-term group was 19.4% (58/299) and 27.6% (55/199) respectively (P=0.046).Donor age and the duration of MMF prophylaxis (short-term group as reference) were associated with EBV viremia according to multivariate analysis [HR=1.022(95%CI 1.006-1.038),1.600(95%CI 1.059-2.418);P=0.006 and 0.026, respectively]. The incidence of grade Ⅱ-Ⅳ and Ⅲ/Ⅳ acute GVHD in long-term and short-term group was 32.2% (64/199) versus 20.7% (62/299)(P=0.005) and 10.1% (20/199) versus 8.0% (24/299) (P=0.427), respectively. Donor sex (female as reference) and duration of MMF prophylaxis (short-term group as reference) were associated with grade Ⅱ-Ⅳ acute GVHD [HR=1.908(95%CI 1.079-3.373),1.752(95%CI 1.161-2.643);P=0.026 and 0.008, respectively].There were no statistical differences in the incidence of CMV viremia, refractory CMV viremia and hemorrhagic cystitis (all P＞0.05) between the two groups. Conclusion: Short-term use of MMF can reduce EBV viremia without increasing the development of acute GVHD in haplo-HSCT patients.